The Grouper and the Bat

The Bat, the grouper half-explained, could not look down.
-Look down? the other grouper asked, his mouth an O.
-For fear of falling, you see. The other didn't.
-In my dreams, he screams in terror. -Yes, I see.
-It's instinct, not desire, that makes him go Eeeee!
and open wide for the bugs. -Could you give me a hint
about the bugs? the other asked. -You ought to know
I can't shake the feeling I'm about to drown.